Cod sursa(job #326860)
Utilizator | Data | 26 iunie 2009 14:36:30 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include<stdio.h>
int n;
char v[2097152];
int main()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
long long i,j,nr=0;
for(i=2;i<=n;i++)
if(v[i]==0)
{
nr++;
for(j=i*i;j<=n;j=j+i)
v[j]=1;
}
printf("%lld\n",nr);
return 0;
}